Valve seat ring



March 5, 1935. A. STOLL VALVE SEAT RING Filed Nov. 9, 1932 iza I jflawsw/l,

?atented Mar, 5, i335 UNITED STATE .VALVE SEAT RING Albert Stoll, Detroit, Mion, assignor to National Machine Products Company, Detroit, Mich,

- a corporation of Michigan Application November 9, 1932, Serial No. 641,915

This invention relates to valve seats for internal combustion engines, and more particularly to that type of valve seat consisting of a ring inserted in the cylinder block of the engine.

I v 5 Valve seats of this type, especially exhaust valve seats, are made from a superior grade of alloy steel so as to provide the .necessary resistance to heat, acid, impact and abrasion and their use allows the cylinder blocks to be made from a soi'ter and therefore more readily machined cast iron. than is possible to employ when the valve seats are made from integral portions of the cylinder block.

Heretofore, valve seats of this type have been made in one piece from superior and costly steel and whether produced in the rough by casting, forging or machining from a bar, require numerous steps looking to the completion of the same and such steps, combined with the fact that the-entire seat is formed of a costly metal, makes theiinserted valve seat an initially expensive addition to an internal combustion engine,

although such cost has been found to be justi- 7 cylinder is cast, and further by the fact that as stated above, such inserted seats make possible the employment of a softer and hence more easily machined cylinder block than is allowed where the seat is formed in the material of the block.

The present invention has for one of its objects the provision of an inserted valve seat ring which,

while possessing all the desirable attributes of a ring made exclusively from high grade and hence costly steel, will be composed of a relatively minor portion of such costly metal and which at the same time may be completed with a less number of successive operations than are required in the manufacture of a one piece ring, all to the end that the composite ring is made commercially available at a cost less than that of the one piece ring.

Also, the construction of the composite ring herein disclosed will be found to be less susceptible to breakage during application and at other times than the ring formed entirely from one piece of steel and to be capable of a mor intimate union with the cylinder block than is possible with a ring composed entirely of a high grade alloy steel, so that in addition to reducing the cost, the employment of a composite ring has material physical advantages over a one piece alloy steel ring.

To attain the foregoing and other objects, the nature of which will appear as the description proceeds, the invention comprehends the provision of a valve seat unit embodying a heat, acid and impact resisting alloy steel ring, which can be punched or formed from sheet stock at a relatively small cost, and a larger lower grade or mild steel ring in which the smaller and higher grade steel ring is embedded in such a manner as to form, a solid unit that may be inserted as such into a motor cylinder block in the same manner as the valve seat madesolely from high speed steel; the smaller ring presenting a hard seat or valve contacting surface, and the larger base or attaching ring, due to the soft and tough nature thereof, reducing the possibility of breakage, and serving to establish a better cohesion between the valve seat and the surrounding cylinder block than was possible with the solid, hard ring heretofore used.

In the accompanying drawing, forming a part of this application, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a vertical sectional view illustrating the sections of-theimproved composite ring in position tobe united through the action of a punch press, 1 Q

Figure 2 is a similar view illustrating the sections joined.

Figure 3 is a fragmentary plan view of the sections of the ring in position to be united,

Figure "4 is a. detail vertical sectional view through the sections of the ring in position to be united,

Figure 5 is a fragmentary plan view 01 the improved composite ring,

Figure 6 is a fragmentary vertical sectional view of the-improved composite ring. I

In the drawing, the numeral 10 designates a base or attaching ring formed from solid or tubular stock of low carbon or mild steel.

It is shown in Figures 1 and 4 that the base or attaching ring 10 has the inner upper comer portion thereof rabbeted to define a seat for a ring 12 of a dissimilar metal. More particularly, the ring 12 is of a superior grade of steel, possibly a tungsten or molybdenum alloy steel having the required heat, acid, impact and abrasion resisting qualities necessary for use in connection with the poppet valves of internal combustion engines, particularly the exhaust valves of such engines.

In carrying out the invention, the ring 12 is formed from flat and suitably thin sheet stock of an alloy steel and such production of the ring may be by way of punching, leaving the ring in the flat form as disclosed in Figs. 1 and 4 for application to the base or attaching ring 10.

Preparatory to the permanent joining of the rings 10 and 12, the same are brought to a forging heat, one that is also a hardening temperature for the high grade steel ring 12 and while at such heat, and with'the parts 10 and 12 loosely connected as shown in Figure 1, the same are placed in the recess 18 of the punch press 18 ing or any other convenient manner.

in position for engagement by the ram 20 and the punch 22, of such press.

It is shown in Figure 1 that the ram 20 is bored as indicated at 24 to receive portions or the rings 10 and 12 and also that the lower portion of the punch 22 is reduced diametrically and shouldered as indicated at 26 so that when the parts of the punch press are brought into the position shown in Figure 2, the ring 12 of a hard alloy steel will be embedded in the softer material forming the base ring 10, producing ledges flatly and securely engaging the inner and outer peripheral edges of the alloy steel ring 12 and at the same time giving to the alloy steel ring the conical or tapered form of a conventional poppet valve seat.

It is important to observe that the descent of the punch and the engagement of the shouldered portion 26 with the alloy steel ring 12 coins the surface of such'seat into practically its finished state so that no further major operations are necessary in the production of the finished seating surface, except of course, the grinding necessary for the provision of companion surfaces between the seat and its mating valve.

Also, it is pointed out that the mild or low carbon steel attaching ring 10 has a greater coefficient of expansion than the steel alloy ring 12 so that the relatively greater or more rapid rate or expansion of the base ring will cause the base ring to shrink securely about the alloy ring during cooling of the parts with the result that an intimate and inseparable union is established between the parts.

With reference-tor F'igures 4 and 6 it will be observed that in addition to the shrink fit of the rings 10 and 12, such parts may be joined by a suitable bonding or brazing material such, for example, as copper, applied by electro-plat- Subsequent to the union of the parts as shown U in Fig. 2, the ram is moved upward a distance ure 6 may be conveniently applied to a cylinder less than the concurrent upward movement of the punch 22 so that the composite ring is stripped from the punch, this being necessary because of the rapid shrinkage of the heated parts as will be apparent to those skilled in the art to which this invention relates.

From Figures 1 and 2, it will be seen that the opposed recesses 16 and 24 are slightly flared toward the meeting portions thereof to provide for theeasy insertion and removal of the parts and the external radial rib formed on the composite ring as an incident to such flaring of the recesses, may be easily removed at the same time the composite ring is brought to the required final external diameter by grinding or otherwise.

In Figure 6, it is shown that the finished valve seat unit is o! a uniform external diameter, ex

cept at the impact ring end thereof, where it is somewhat reduced so as to define an annular shoulder into engagement with which a portion of the engine casting may be pe'ened.

The finished composite seat disclosed in Figblock and by reason of the mild nature of the material forming the attaching ring 10 as distinguished from the hardness and brittleness of the alloy steel ring 12, a more perfect cohesion between the composite ring and the surrounding iron of the cylinder block is brought about than is possible in inserted valve seats of conventional design where the ring is formed entirely of a tungsten or molybdenum alloy steel. More specifically, those walls of the bi-metallic valve seat unit which engage the engine casting are of the material forming the soft and tough base ring 10 and such material is more suited to effective cohesion with the iron of the engine casting than is the hard metal of the impact ring.

With reference to the foregoing description taken in connection with the accompanying drawing, it will be apparent that the composite ring forming the subject of this application has all the advantages of -a one-piece alloy steel ring such, for example, as effective resistance to heat, acid, and impact, while such composite ring is not so susceptible to breakage as a one piece ring and hence, may be applied to a cylinder block in a highly expeditious manner, attention in this latter regard being invited to the fact that the soft and tough nature of the outer or base ring 10 so reduces the possibility of breakage that the operation of seating the unit may be speedily performed.

In addition to possessing the physical advantages of a one-piece alloy steel ring, without the disadvantages that are known to accompany the one-piece alloy ring, the composite ring herein disclosed, embodying as it does, but a minor portion of relatively expensive metal, may be produced at a cost less than that of the one-piece In summarizing, it will be seen that the article forming the subject of this application is in the nature of an annulus having a downwardly and inwardly beveled valve seating upper surface and such annulus is composed of a base or attaching ring of a mild or low carbon steel in which the imp ct ring of a superior alloy steel is embedded form the valve seat with portions of the base ring positioned in firm restraining engagement with the inner and outer peripheral edges of the impact ring to hold the impact ring in place, it being noted in this connection that a portion of the base ring actually overhangs the impact ring holding the impact ring against either axial or transverse movement with respect to the base ring. That is to say, the impact ring is embedded in the underlying base ring with portions of the base ring engaging the inner and outer peripheral edges of the impact ring to define ledges and it is important to observe that these ledges extend at an acute angle to the longitudinal axis of the composite ring or are inclined with respect to such longitudinal axis. By reason of this constructiomthe outer ledge actually overhangs a portion of the impact ring and thereby cooperates with the underlying portion of the base ring in holding the impact ring against movement with respect to the base ring, notwithstanding temperature changes and other contrary influences incident to use.

Having thus described the invention, what is claimed is:-

1. In a valve seat unit for the poppet valves of internal combustion engines, a bi-metallic annulus having a downwardly and inwardly beveled surface forming a seat for the poppet valve of an internal combustion engine, said annulus embodying a metallic attaching base ring and an initially separate and harder metallic impact ring embedded in the base ring and having a beveled upper surface constituting said seat, a portion of said base ring being in overhanging confining relation said impact ring.

2. in a valve seat unit for the poppet valves of internal combustion engines, a bi-metallic an nulus having a downwardly and inwardly inclined upper surface forming a seat for the poppet valve of an internal combustion engine, said annulus embodying an outer metallic attaching base ring having an annular recess provided with side walls and a downwardly and inwardly inclined bottom wall, and an impact inner ring of an alloy steel in said recess closely between said side walls and flatly in engagement with said transversely inclined bottom wall and having a beveled upper surface forming said seat, said outer metallic attaching base ring being of a metal softer and tougher than .that of the impact ring first for effective cohesion with the material of an engine cylinder and second for protecting the impact ring against breakage during and after application of the bi-metallic annulus.

3. In a valve seat unit for the poppet valves of internal combustion engines, a bl-metallic annulus having a downwardly and inwardly inclined upper surface forming a seat for the poppet valve of an internal combustion engine, said annulus embodying a metallic base ring having an annular recess provided with side walls inclined with respect to the longitudinal axis of the base ring and a downwardly and inwardly inclined bottom wall, and a harder impact ring in said recess closely between the inclined side walls and flatly in engagement with said transversely inclined bottom wall and having a beveled upper surface forming said seat, said impact ring being of a metal having heat, acid and impact resisting qualities superior to those of the base ring.

4. In a valve seat unit for application to an internal combustion engine casting, abi-metallic annulus having a tough metallic attaching ring having a recess opening out through one end and the inner peripheral wall thereof and a hard metal impact ring in said recess and surrounded on the inner and outer edges and .on the base side thereof by the tough metal of the attaching ring.

5. In a valve seat unit for application to an internal combustion engine casting a bi-metallic annulus having a tough metallic attaching ring having a recess opening out through one end and the inner peripheral wall thereof and at a point spaced inward of the outer perlpheul wall thereof, and a hard metal impact ring in said recess and surrounded on the inner and outer edges and on the base side thereof by the tough metal of the attaching ring.

6. In a valve seat unit for application to an internal combustion engine casting, a bi-metallic annulus having a tough metallic attaching ring having a recess opening'out through one end and the inner peripheral wall thereof and at a point spaced inward of the outer peripheral wall thereof, and a hard metal impact ring in said recess and surrounded on the inner and outer edges and on the base side thereof by the tough metal of the attaching ring, the outer peripheral portion of the attaching ring being in overhanging and embracing relation to the impact ring holdingthe impact and attaching rings firmly together for handling and application as a. unit and protecting the impact ring against direct engagement by the material of the engine casting.

7. In a valve seat unit of the type applied to internal combustion engine castings, a bi-metallic annulus embodying a metallic attaching outer ring of a metal tougher than that of the engine casting to which the bi-metallic annulus is to be applied, and a harder metal inner impact ring embedded in the attaching outer ring and bounded on the base, inner and outer sides thereof by the tough metal of the attaching ring.

8. In a valve seat unit of the type applied to internal combustion engine castings, a bi-metallic annulus embodying a metallic attachin outer ring of a metal tougher than that of the engine casting to which the bi-metallic annulus is to be applied, and a harder metal inner impact ring embedded in the attaching outer ring and bounded on the base, inner and outer sides thereof by the tough metal of the attaching ring, a portion of the attaching ring being in overhanging, embracing, and retaining relation to a portion of the impact ring thereby uniting both rings to be handled together and applied as a unit.

9. In a valve seat unit for application to an internal combustion engine casting, a bi-metallic annulus embodying an attaching outer ring having a recess formed-with inner and outer walls, said annulus also embodyin an impact inner ring positioned closely in said recess between said inner and outer walls thereof, said outer wall of the recess being in overhanging relation to the outer peripheral portion of the impact ring thereby uniting the impact and attaching rings to be handled together and applied as a unit, said side walls of the recess and opposed surfaces of the impact ring being disposed at acute angles to the axis of the bi-metallic annulus.

10. In a valve seat unit of the type for insertion in an internal combustion engine casting, a bi-metallic annulus embodying a metallic attaching outer ring of a metal tougher than that of the engine casting to which the bi-metallic annulus is to be applied and a harder metal inner impact ring embedded in one end of the attaching ring and closely surrounded and engaged on a multiplicity of sides thereby, said attaching ring being externally reduced at the impact ring end thereof to form an external shoulder.

11. In an inserted valve seat for poppet valves of internal combustion engines, an impact ring, and a base ring underlying the impact ring and having a recess snugly receiving the impact ring, and having an outer wall in closely embracing and overhanging relation to a portion of the impact ring to cooperate with the underlying portion of the base ring in securing the impact ring in place.

12. In an inserted valve seat for poppet valves of internal combustion engines, an impact ring having inner and outer edges and a base ring underlying the impact ring and having inner and outer ledges in close contact with the inner and outer edges of the impact ring, one of said ledges of the base ring closely overhangi a portion of the impact ring thereby cooperating with the underlying portion of the base ring in securing the impact ring in place.

13. In an inserted valve seat for popp t valves- 

